System for neuronavigation registration and robotic trajectory guidance, robotic surgery, and related methods and devices

ABSTRACT

A system of robotic surgery includes components capable of drilling a bore in the cranium of a patient in connection with craniotomy and other cranial surgeries. A perforator associated with such system is controlled by suitable computer-implemented instructions to maintain the perforator tip along a desired trajectory line while moving the perforator bit at locations proximal to such perforator tip in a circular motion, thereby imparting a conical oscillation to the perforator bit relative to the trajectory line. The angle at which the perforator bit is oscillated relative to such trajectory line results in the bore formed in the cranium having a diameter larger than the bit diameter, and the larger diameter and related conical oscillation is selected so as to reduce frictional force opposing withdrawal of the bit from the situs of the bore, thereby reducing the risk of jamming of the bit during its associated operations.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of U.S. patent applicationSer. No. 16/452,737, filed Jun. 26, 2019, which is acontinuation-in-part of U.S. patent application Ser. No. 16/361,863,filed on Mar. 22, 2019, the entire contents of each of which are herebyincorporated herein by reference for all purposes.

FIELD

The present disclosure relates to medical devices and systems, and moreparticularly, systems for neuronavigation registration and robotictrajectory guidance, robotic surgery, and related methods and devices.

BACKGROUND

Position recognition systems for robot assisted surgeries are used todetermine the position of and track a particular object in 3-dimensions(3D). In robot assisted surgeries, for example, certain objects, such assurgical instruments, need to be tracked with a high degree of precisionas the instrument is being positioned and moved by a robot or by aphysician, for example.

Position recognition systems may use passive and/or active sensors ormarkers for registering and tracking the positions of the objects. Usingthese sensors, the system may geometrically resolve the 3-dimensionalposition of the sensors based on information from or with respect to oneor more cameras, signals, or sensors, etc. These surgical systems cantherefore utilize position feedback to precisely guide movement ofrobotic arms and tools relative to a patients' surgical site. Thus,there is a need for a system that efficiently and accurately provideneuronavigation registration and robotic trajectory guidance in asurgical environment.

End-effectors used in robotic surgery may be limited to use in onlycertain procedures, or may suffer from other drawbacks or disadvantages.

Cranial surgery such as electrode placement for deep brain stimulation(DBS) typically involves drilling a hole in the cranium using aspecialized drill called a perforator, the perforator having anassociated elongated perforator bit. The cranial perforator has a clutchthat causes its sharp bit to engage (rotate) when there is resistance toforward thrust and to stop rotating once penetration past the internalwall of the skull is achieved, preventing the drill from damaging thebrain once the craniotomy hole has been made.

An unwanted consequence of the halting of rotation of the perforator isthat the bit may become jammed in the hole that it has created, and maybe difficult to remove. A surgical technique for preventing jamming ofthe perforator is to apply slight conical rotation to the perforatorduring drilling. The hole that is created while using this technique isslightly conically shaped instead of being cylindrical but still allowsgood attachment of the housing of the electrode holder.

Poor surgical technique when applying conical motion during perforatorusage could lead to poor outcome. Too large of a conical motion couldcause the hole to be larger than desired. Too small of a conical motioncould cause the hole to be too cylindrical and therefore not effectivelyprevent jamming of the bit. Uneven conical motion could lead to an oddlyshaped hole that does not hold the electrode housing well.

SUMMARY

According to some implementations, a surgical robot system is configuredfor surgery on an anatomical feature of a patient, and includes asurgical robot, a robot arm connected to such surgical robot, and anend-effector connected to the robot arm.

According to some embodiments of inventive concepts, a system includes aprocessor circuit and a memory coupled to the processor circuit. Thememory includes machine-readable instructions configured to cause theprocessor circuit to determine, based on a first image volume comprisingan anatomical feature of a patient, a registration fixture that is fixedwith respect to the anatomical feature of the patient, and a firstplurality of fiducial markers that are fixed with respect to theregistration fixture, determine, for each fiducial marker of the firstplurality of fiducial markers, a position of the fiducial markerrelative to the image volume. The machine-readable instructions arefurther configured to cause the processor circuit to determine, based onthe determined positions of the first plurality of fiducial markers, aposition and orientation of the registration fixture with respect to theanatomical feature. The machine-readable instructions are furtherconfigured to cause the processor circuit to, based on a data frame froma tracking system comprising a second plurality of tracking markers thatare fixed with respect to the registration fixture, determine, for eachtracking marker of the second plurality of tracking markers, a positionof the tracking marker. The machine-readable instructions are furtherconfigured to cause the processor circuit to determine, based on thedetermined positions of the second plurality of tracking markers, aposition and orientation of the registration fixture with respect to arobot arm of a surgical robot. The machine-readable instructions arefurther configured to cause the processor circuit to determine, based onthe determined position and orientation of the registration fixture withrespect to the anatomical feature and the determined position andorientation of the registration fixture with respect to the robot arm, aposition and orientation of the anatomical feature with respect to therobot arm. The machine-readable instructions are further configured tocause the processor circuit to control the robot arm based on thedetermined position and orientation of the anatomical feature withrespect to the robot arm.

According to some other embodiments of inventive concepts, acomputer-implemented method is disclosed. The computer-implementedmethod includes, based on a first image volume comprising an anatomicalfeature of a patient, a registration fixture that is fixed with respectto the anatomical feature of the patient, and a first plurality offiducial markers that are fixed with respect to the registrationfixture, determining, for each fiducial marker of the first plurality offiducial markers, a position of the fiducial marker. Thecomputer-implemented method further includes determining, based on thedetermined positions of the first plurality of fiducial markers, aposition and orientation of the registration fixture with respect to theanatomical feature. The computer-implemented method further includes,based on a tracking data frame comprising a second plurality of trackingmarkers that are fixed with respect to the registration fixture,determining, for each tracking marker of the second plurality oftracking markers, a position of the tracking marker. Thecomputer-implemented method further includes determining, based on thedetermined positions of the second plurality of tracking markers, aposition and orientation of the registration fixture with respect to arobot arm of a surgical robot. The computer-implemented method furtherincludes determining, based on the determined position and orientationof the registration fixture with respect to the anatomical feature andthe determined position and orientation of the registration fixture withrespect to the robot arm, a position and orientation of the anatomicalfeature with respect to the robot arm. The computer-implemented methodfurther includes controlling the robot arm based on the determinedposition and orientation of the anatomical feature with respect to therobot arm.

According to some other embodiments of inventive concepts, a surgicalsystem is disclosed. The surgical system includes an intraoperativesurgical tracking computer having a processor circuit and a memory. Thememory includes machine-readable instructions configured to cause theprocessor circuit to provide a medical image volume defining an imagespace. The medical image volume includes an anatomical feature of apatient, a registration fixture that is fixed with respect to theanatomical feature of the patient, and a plurality of fiducial markersthat are fixed with respect to the registration fixture. Themachine-readable instructions are further configured to cause theprocessor circuit to, based on the medical image volume, determine, foreach fiducial marker of the plurality of fiducial markers, a position ofthe fiducial marker with respect to the image space. Themachine-readable instructions are further configured to cause theprocessor circuit to determine, based on the determined positions of theplurality of fiducial markers, a position and orientation of theregistration fixture with respect to the anatomical feature. Themachine-readable instructions are further configured to cause theprocessor circuit to provide a tracking data frame defining a trackingspace, the tracking data frame comprising positions of a first pluralityof tracked markers that are fixed with respect to the registrationfixture. The machine-readable instructions are further configured tocause the processor circuit to, based on the tracking data frame,determine a position of the anatomical feature with respect to the firstplurality of tracked markers in the tracking space. The surgical systemfurther includes a surgical robot having a robot arm configured toposition a surgical end-effector. The surgical robot further includes acontroller connected to the robot arm. The controller is configured toperform operations including, based on the tracking data frame,determining a position of the robot arm with respect to the trackingspace. The controller is configured to perform operations includingdetermining, based on the determined position and orientation of theanatomical feature with respect to the tracking space and the determinedposition and orientation of the robot arm with respect to the trackingspace, a position and orientation of the anatomical feature with respectto the robot arm. The controller is configured to perform operationsincluding controlling movement of the robot arm based on the determinedposition and orientation of the anatomical feature with respect to therobot arm to position the surgical end-effector relative to a locationon the patient to facilitate surgery on the patient.

In accordance with one possible implementation, a surgical robot systemis provided for performing various operations on a patient, such asbrain surgery, such brain surgery including the possibility of drillinga hole in a cranium of a patient in connection with such cranialsurgery. The robot system includes certain features to address variouspotential drawbacks and disadvantages associated with perforation of theskull and craniotomy. The surgical system includes a surgical robot anda robot arm connected to such surgical robot. The surgical robot systemfurther includes an end-effector in any number of suitableconfigurations, such end-effector being orientable so as to oppose thecranium to be operated upon, the end-effector is positioned in operativeproximity to the cranium.

In such implementations, a perforator may be connected to theend-effector and the perforator is adapted or otherwise configured to beadvanced or withdrawn relative to the cranium by suitable features. Theperforator has an elongated perforator bit which terminates in a sharp,perforator tip. The bit has an associated bit diameter, and theperforator has a clutch operable to rotate the bit in response todetection by the surgical robot of resistance during advancement of thebit and further operable to stop bit rotation in response to detectionby the surgical robot of penetration past an internal wall of thecranium.

Suitable electronic or computer implemented instructions are associatedwith the robot system, including, for example, a processor circuit and amemory accessible by the processor circuit and having machine-readableinstructions associated therewith.

Accordingly, various operations of the surgical robot system inconnection with the drilling of a hole in a cranium may be controlled orotherwise executed by suitable machine-readable instructions. Forexample, in certain implementations, machine-readable instructions maycause the perforator to maintain the perforator tip along a trajectoryline associated with the perforation. While maintaining the perforatedtip along such trajectory line, the machine-readable instructionsfurther cause the perforator bit itself to move in a conical oscillationrelative to the trajectory line during the advancement of the bit intothe cranium. In other words, the elongated perforator bit is angledrelative to such trajectory line so as to trace a cone whose tipcorresponds substantially to the perforator tip. By virtue of suchconical oscillation, a substantially circular bore is formed in thecranium through which the bit has been advanced, but such bore, byvirtue of the conical oscillation, has a diameter larger than the bitdiameter. The conical oscillation and associated angle are selected ordetermined so that the resulting bore diameter is larger than the bitdiameter by an amount to reduce frictional force opposing withdrawal ofthe bit from the bore after penetration of the inner wall of thecranium. In this way, the risk of jamming of the perforator bit duringcranium perforation is reduced.

In certain suitable implementations, the machine-readable instructions,when executed, cause the conical oscillation of the perforator to occurat an angle relative to the trajectory line ranging from about 1° toabout 3°, and in certain implementations, an angle of about 2° has beenfound suitable.

In accordance with still other implementations, the above-describedconical oscillation is associated with a perforator mode, and suchperforator mode may be associated with machine-readable instructionswhich are user selectable through an associated user interface.

Still other implementations of a robot system capable of drilling a holein a cranium may include a robot arm with a robot wrist and a load celloperatively associated with such robot wrist. In this implementation,the load cell senses reactive, that is, opposing force which correspondsto the perforator bit engaging the cranium. The load cell may be furtherconfigured so as to detect a reduction in such reactive force by apredetermined amount. That predetermined amount corresponds generally tothe force reduction corresponding to achieving perforation, such as bypenetrating the inner wall of the cranium. Upon such detection, thesystem may generate either a user-perceptible signal so as to warn theuser or operator to cease manual advancement or an input to the systemso that machine-readable instructions cease automatic advancement of theperforator and potentially withdraw such perforator away from thecranium.

While certain implementations of the system may impart the conicaloscillation by movement of the robot arm or the robot wrist itself,other implementations may include a linear slide which can be angled soas to define the appropriate cone for conical oscillation, rotated, thatis, orbited about a selected trajectory line, and advanced bytranslation of the linear slide toward the cranium being operated upon,and subsequently withdrawn upon completion or perforation of the desiredprocedure.

Other methods and related devices and systems, and corresponding methodsand computer program products according to embodiments will be or becomeapparent to one with skill in the art upon review of the followingdrawings and detailed description. It is intended that all such devicesand systems, and corresponding methods and computer program products beincluded within this description, be within the scope of the presentdisclosure, and be protected by the accompanying claims. Moreover, it isintended that all embodiments disclosed herein can be implementedseparately or combined in any way and/or combination.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the disclosure and are incorporated and constitute apart of this application, illustrate certain non-limiting embodiments ofinventive concepts. In the drawings:

FIG. 1A is an overhead view of an arrangement for locations of a roboticsystem, patient, surgeon, and other medical personnel during a surgicalprocedure, according to some embodiments;

FIG. 1B is an overhead view of an alternate arrangement for locations ofa robotic system, patient, surgeon, and other medical personnel during acranial surgical procedure, according to some embodiments;

FIG. 2 illustrates a robotic system including positioning of thesurgical robot and a camera relative to the patient according to someembodiments;

FIG. 3 is a flowchart diagram illustrating computer-implementedoperations for determining a position and orientation of an anatomicalfeature of a patient with respect to a robot arm of a surgical robot,according to some embodiments;

FIG. 4 is a diagram illustrating processing of data for determining aposition and orientation of an anatomical feature of a patient withrespect to a robot arm of a surgical robot, according to someembodiments;

FIGS. 5A-5C illustrate a system for registering an anatomical feature ofa patient using a computerized tomography (CT) localizer, a framereference array (FRA), and a dynamic reference base (DRB), according tosome embodiments;

FIGS. 6A and 6B illustrate a system for registering an anatomicalfeature of a patient using fluoroscopy (fluoro) imaging, according tosome embodiments;

FIG. 7 illustrates a system for registering an anatomical feature of apatient using an intraoperative CT fixture (ICT) and a DRB, according tosome embodiments;

FIGS. 8A and 8B illustrate systems for registering an anatomical featureof a patient using a DRB and an X-ray cone beam imaging device,according to some embodiments;

FIG. 9 illustrates a system for registering an anatomical feature of apatient using a navigated probe and fiducials for point-to-point mappingof the anatomical feature, according to some embodiments;

FIG. 10 illustrates a two-dimensional visualization of an adjustmentrange for a centerpoint-arc mechanism, according to some embodiments;

FIG. 11 illustrates a two-dimensional visualization of virtual pointrotation mechanism, according to some embodiments;

FIG. 12 is an isometric view of one possible implementation of anend-effector according to the present disclosure;

FIG. 13 is an isometric view of another possible implementation of anend-effector of the present disclosure;

FIG. 14 is a partial cutaway, isometric view of still another possibleimplementation of an end-effector according to the present disclosure;

FIG. 15 is a bottom angle isometric view of yet another possibleimplementation of an end-effector according to the present disclosure;

FIG. 16 is an isometric view of one possible tool stop for use with anend-effector according to the present disclosure;

FIGS. 17 and 18 are top plan views of one possible implementation of atool insert locking mechanism of an end-effector according to thepresent disclosure;

FIGS. 19 and 20 are top plan views of the tool stop of FIG. 16, showingopen and closed positions, respectively.

FIGS. 21 and 22 are schematic views of further implementations of therobotic system disclosed herein, including a surgical tool comprising aperforator.

DETAILED DESCRIPTION

It is to be understood that the present disclosure is not limited in itsapplication to the details of construction and the arrangement ofcomponents set forth in the description herein or illustrated in thedrawings. The teachings of the present disclosure may be used andpracticed in other embodiments and practiced or carried out in variousways. Also, it is to be understood that the phraseology and terminologyused herein is for the purpose of description and should not be regardedas limiting. The use of “including,” “comprising,” or “having” andvariations thereof herein is meant to encompass the items listedthereafter and equivalents thereof as well as additional items. Unlessspecified or limited otherwise, the terms “mounted,” “connected,”“supported,” and “coupled” and variations thereof are used broadly andencompass both direct and indirect mountings, connections, supports, andcouplings. Further, “connected” and “coupled” are not restricted tophysical or mechanical connections or couplings.

The following discussion is presented to enable a person skilled in theart to make and use embodiments of the present disclosure. Variousmodifications to the illustrated embodiments will be readily apparent tothose skilled in the art, and the principles herein can be applied toother embodiments and applications without departing from embodiments ofthe present disclosure. Thus, the embodiments are not intended to belimited to embodiments shown, but are to be accorded the widest scopeconsistent with the principles and features disclosed herein. Thefollowing detailed description is to be read with reference to thefigures, in which like elements in different figures have like referencenumerals. The figures, which are not necessarily to scale, depictselected embodiments and are not intended to limit the scope of theembodiments. Skilled artisans will recognize the examples providedherein have many useful alternatives and fall within the scope of theembodiments.

According to some other embodiments, systems for neuronavigationregistration and robotic trajectory guidance, and related methods anddevices are disclosed. In some embodiments, a first image having ananatomical feature of a patient, a registration fixture that is fixedwith respect to the anatomical feature of the patient, and a firstplurality of fiducial markers that are fixed with respect to theregistration fixture is analyzed, and a position is determined for eachfiducial marker of the first plurality of fiducial markers. Next, basedon the determined positions of the first plurality of fiducial markers,a position and orientation of the registration fixture with respect tothe anatomical feature is determined. A data frame comprising a secondplurality of tracking markers that are fixed with respect to theregistration fixture is also analyzed, and a position is determined foreach tracking marker of the second plurality of tracking markers. Basedon the determined positions of the second plurality of tracking markers,a position and orientation of the registration fixture with respect to arobot arm of a surgical robot is determined. Based on the determinedposition and orientation of the registration fixture with respect to theanatomical feature and the determined position and orientation of theregistration fixture with respect to the robot arm, a position andorientation of the anatomical feature with respect to the robot arm isdetermined, which allows the robot arm to be controlled based on thedetermined position and orientation of the anatomical feature withrespect to the robot arm.

Advantages of this and other embodiments include the ability to combineneuronavigation and robotic trajectory alignment into one system, withsupport for a wide variety of different registration hardware andmethods. For example, as will be described in detail below, embodimentsmay support both computerized tomography (CT) and fluoroscopy (fluoro)registration techniques, and may utilize frame-based and/or framelesssurgical arrangements. Moreover, in many embodiments, if an initial(e.g. preoperative) registration is compromised due to movement of aregistration fixture, registration of the registration fixture (and ofthe anatomical feature by extension) can be re-establishedintraoperatively without suspending surgery and re-capturingpreoperative images.

Referring now to the drawings, FIG. 1A illustrates a surgical robotsystem 100 in accordance with an embodiment. Surgical robot system 100may include, for example, a surgical robot 102, one or more robot arms104, a base 106, a display 110, an end-effector 112, for example,including a guide tube 114, and one or more tracking markers 118. Therobot arm 104 may be movable along and/or about an axis relative to thebase 106, responsive to input from a user, commands received from aprocessing device, or other methods. The surgical robot system 100 mayinclude a patient tracking device 116 also including one or moretracking markers 118, which is adapted to be secured directly to thepatient 210 (e.g., to a bone of the patient 210). As will be discussedin greater detail below, the tracking markers 118 may be secured to ormay be part of a stereotactic frame that is fixed with respect to ananatomical feature of the patient 210. The stereotactic frame may alsobe secured to a fixture to prevent movement of the patient 210 duringsurgery.

According to an alternative embodiment, FIG. 1B is an overhead view ofan alternate arrangement for locations of a robotic system 100, patient210, surgeon 120, and other medical personnel during a cranial surgicalprocedure. During a cranial procedure, for example, the robot 102 may bepositioned behind the head 128 of the patient 210. The robot arm 104 ofthe robot 102 has an end-effector 112 that may hold a surgicalinstrument 108 during the procedure. In this example, a stereotacticframe 134 is fixed with respect to the patient's head 128, and thepatient 210 and/or stereotactic frame 134 may also be secured to apatient base 211 to prevent movement of the patient's head 128 withrespect to the patient base 211. In addition, the patient 210, thestereotactic frame 134 and/or or the patient base 211 may be secured tothe robot base 106, such as via an auxiliary arm 107, to preventrelative movement of the patient 210 with respect to components of therobot 102 during surgery. Different devices may be positioned withrespect to the patient's head 128 and/or patient base 211 as desired tofacilitate the procedure, such as an intra-operative CT device 130, ananesthesiology station 132, a scrub station 136, a neuro-modulationstation 138, and/or one or more remote pendants 140 for controlling therobot 102 and/or other devices or systems during the procedure.

The surgical robot system 100 in the examples of FIGS. 1A and/or 1B mayalso use a sensor, such as a camera 200, for example, positioned on acamera stand 202. The camera stand 202 can have any suitableconfiguration to move, orient, and support the camera 200 in a desiredposition. The camera 200 may include any suitable camera or cameras,such as one or more cameras (e.g., bifocal or stereophotogrammetriccameras), able to identify, for example, active or passive trackingmarkers 118 (shown as part of patient tracking device 116 in FIG. 2) ina given measurement volume viewable from the perspective of the camera200. In this example, the camera 200 may scan the given measurementvolume and detect the light that comes from the tracking markers 118 inorder to identify and determine the position of the tracking markers 118in three-dimensions. For example, active tracking markers 118 mayinclude infrared-emitting markers that are activated by an electricalsignal (e.g., infrared light emitting diodes (LEDs)), and/or passivetracking markers 118 may include retro-reflective markers that reflectinfrared or other light (e.g., they reflect incoming IR radiation intothe direction of the incoming light), for example, emitted byilluminators on the camera 200 or other suitable sensor or other device.

In many surgical procedures, one or more targets of surgical interest,such as targets within the brain for example, are localized to anexternal reference frame. For example, stereotactic neurosurgery may usean externally mounted stereotactic frame that facilitates patientlocalization and implant insertion via a frame mounted arc.Neuronavigation is used to register, e.g., map, targets within the brainbased on pre-operative or intraoperative imaging. Using thispre-operative or intraoperative imaging, links and associations can bemade between the imaging and the actual anatomical structures in asurgical environment, and these links and associations can be utilizedby robotic trajectory systems during surgery.

According to some embodiments, various software and hardware elementsmay be combined to create a system that can be used to plan, register,place and verify the location of an instrument or implant in the brain.These systems may integrate a surgical robot, such as the surgical robot102 of FIGS. 1A and/or 1B, and may employ a surgical navigation systemand planning software to program and control the surgical robot. Inaddition or alternatively, the surgical robot 102 may be remotelycontrolled, such as by nonsterile personnel.

The robot 102 may be positioned near or next to patient 210, and it willbe appreciated that the robot 102 can be positioned at any suitablelocation near the patient 210 depending on the area of the patient 210undergoing the operation. The camera 200 may be separated from thesurgical robot system 100 and positioned near or next to patient 210 aswell, in any suitable position that allows the camera 200 to have adirect visual line of sight to the surgical field 208. In theconfiguration shown, the surgeon 120 may be positioned across from therobot 102, but is still able to manipulate the end-effector 112 and thedisplay 110. A surgical assistant 126 may be positioned across from thesurgeon 120 again with access to both the end-effector 112 and thedisplay 110. If desired, the locations of the surgeon 120 and theassistant 126 may be reversed. The traditional areas for theanesthesiologist 122 and the nurse or scrub tech 124 may remainunimpeded by the locations of the robot 102 and camera 200.

With respect to the other components of the robot 102, the display 110can be attached to the surgical robot 102 and in other embodiments, thedisplay 110 can be detached from surgical robot 102, either within asurgical room with the surgical robot 102, or in a remote location. Theend-effector 112 may be coupled to the robot arm 104 and controlled byat least one motor. In some embodiments, end-effector 112 can comprise aguide tube 114, which is able to receive and orient a surgicalinstrument 108 used to perform surgery on the patient 210. As usedherein, the term “end-effector” is used interchangeably with the terms“end-effectuator” and “effectuator element.” Although generally shownwith a guide tube 114, it will be appreciated that the end-effector 112may be replaced with any suitable instrumentation suitable for use insurgery. In some embodiments, end-effector 112 can comprise any knownstructure for effecting the movement of the surgical instrument 108 in adesired manner.

The surgical robot 102 is able to control the translation andorientation of the end-effector 112. The robot 102 is able to moveend-effector 112 along x-, y-, and z-axes, for example. The end-effector112 can be configured for selective rotation about one or more of thex-, y-, and z-axis such that one or more of the Euler Angles (e.g.,roll, pitch, and/or yaw) associated with end-effector 112 can beselectively controlled. In some embodiments, selective control of thetranslation and orientation of end-effector 112 can permit performanceof medical procedures with significantly improved accuracy compared toconventional robots that use, for example, a six degree of freedom robotarm comprising only rotational axes. For example, the surgical robotsystem 100 may be used to operate on patient 210, and robot arm 104 canbe positioned above the body of patient 210, with end-effector 112selectively angled relative to the z-axis toward the body of patient210.

In some embodiments, the position of the surgical instrument 108 can bedynamically updated so that surgical robot 102 can be aware of thelocation of the surgical instrument 108 at all times during theprocedure. Consequently, in some embodiments, surgical robot 102 canmove the surgical instrument 108 to the desired position quickly withoutany further assistance from a physician (unless the physician sodesires). In some further embodiments, surgical robot 102 can beconfigured to correct the path of the surgical instrument 108 if thesurgical instrument 108 strays from the selected, preplanned trajectory.In some embodiments, surgical robot 102 can be configured to permitstoppage, modification, and/or manual control of the movement ofend-effector 112 and/or the surgical instrument 108. Thus, in use, insome embodiments, a physician or other user can operate the system 100,and has the option to stop, modify, or manually control the autonomousmovement of end-effector 112 and/or the surgical instrument 108. Furtherdetails of surgical robot system 100 including the control and movementof a surgical instrument 108 by surgical robot 102 can be found inco-pending U.S. Patent Publication No. 2013/0345718, which isincorporated herein by reference in its entirety.

As will be described in greater detail below, the surgical robot system100 can comprise one or more tracking markers configured to track themovement of robot arm 104, end-effector 112, patient 210, and/or thesurgical instrument 108 in three dimensions. In some embodiments, aplurality of tracking markers can be mounted (or otherwise secured)thereon to an outer surface of the robot 102, such as, for example andwithout limitation, on base 106 of robot 102, on robot arm 104, and/oron the end-effector 112. In some embodiments, such as the embodiment ofFIG. 3 below, for example, one or more tracking markers can be mountedor otherwise secured to the end-effector 112. One or more trackingmarkers can further be mounted (or otherwise secured) to the patient210. In some embodiments, the plurality of tracking markers can bepositioned on the patient 210 spaced apart from the surgical field 208to reduce the likelihood of being obscured by the surgeon, surgicaltools, or other parts of the robot 102. Further, one or more trackingmarkers can be further mounted (or otherwise secured) to the surgicalinstruments 108 (e.g., a screw driver, dilator, implant inserter, or thelike). Thus, the tracking markers enable each of the marked objects(e.g., the end-effector 112, the patient 210, and the surgicalinstruments 108) to be tracked by the surgical robot system 100. In someembodiments, system 100 can use tracking information collected from eachof the marked objects to calculate the orientation and location, forexample, of the end-effector 112, the surgical instrument 108 (e.g.,positioned in the tube 114 of the end-effector 112), and the relativeposition of the patient 210. Further details of surgical robot system100 including the control, movement and tracking of surgical robot 102and of a surgical instrument 108 can be found in U.S. Patent PublicationNo. 2016/0242849, which is incorporated herein by reference in itsentirety.

In some embodiments, pre-operative imaging may be used to identify theanatomy to be targeted in the procedure. If desired by the surgeon theplanning package will allow for the definition of a reformattedcoordinate system. This reformatted coordinate system will havecoordinate axes anchored to specific anatomical landmarks, such as theanterior commissure (AC) and posterior commissure (PC) for neurosurgeryprocedures. In some embodiments, multiple pre-operative exam images(e.g., CT or magnetic resonance (MR) images) may be co-registered suchthat it is possible to transform coordinates of any given point on theanatomy to the corresponding point on all other pre-operative examimages.

As used herein, registration is the process of determining thecoordinate transformations from one coordinate system to another. Forexample, in the co-registration of preoperative images, co-registering aCT scan to an MR scan means that it is possible to transform thecoordinates of an anatomical point from the CT scan to the correspondinganatomical location in the MR scan. It may also be advantageous toregister at least one exam image coordinate system to the coordinatesystem of a common registration fixture, such as a dynamic referencebase (DRB), which may allow the camera 200 to keep track of the positionof the patient in the camera space in real-time so that anyintraoperative movement of an anatomical point on the patient in theroom can be detected by the robot system 100 and accounted for bycompensatory movement of the surgical robot 102.

FIG. 3 is a flowchart diagram illustrating computer-implementedoperations 300 for determining a position and orientation of ananatomical feature of a patient with respect to a robot arm of asurgical robot, according to some embodiments. The operations 300 mayinclude receiving a first image volume, such as a CT scan, from apreoperative image capture device at a first time (Block 302). The firstimage volume includes an anatomical feature of a patient and at least aportion of a registration fixture that is fixed with respect to theanatomical feature of the patient. The registration fixture includes afirst plurality of fiducial markers that are fixed with respect to theregistration fixture. The operations 300 further include determining,for each fiducial marker of the first plurality of fiducial markers, aposition of the fiducial marker relative to the first image volume(Block 304). The operations 300 further include, determining, based onthe determined positions of the first plurality of fiducial markers,positions of an array of tracking markers on the registration fixture(fiducial registration array or FRA) with respect to the anatomicalfeature (Block 306).

The operations 300 may further include receiving a tracking data framefrom an intraoperative tracking device comprising a plurality oftracking cameras at a second time that is later than the first time(Block 308). The tracking frame includes positions of a plurality oftracking markers that are fixed with respect to the registration fixture(FRA) and a plurality of tracking markers that are fixed with respect tothe robot. The operations 300 further include determining, for based onthe positions of tracking markers of the registration fixture, aposition and orientation of the anatomical feature with respect to thetracking cameras (Block 310). The operations 300 further includedetermining, based on the determined positions of the plurality oftracking markers on the robot, a position and orientation of the robotarm of a surgical robot with respect to the tracking cameras (Block312).

The operations 300 further include determining, based on the determinedposition and orientation of the anatomical feature with respect to thetracking cameras and the determined position and orientation of therobot arm with respect to the tracking cameras, a position andorientation of the anatomical feature with respect to the robot arm(Block 314). The operations 300 further include controlling movement ofthe robot arm with respect to the anatomical feature, e.g., along and/orrotationally about one or more defined axis, based on the determinedposition and orientation of the anatomical feature with respect to therobot arm (Block 316).

FIG. 4 is a diagram illustrating a data flow 400 for a multiplecoordinate transformation system, to enable determining a position andorientation of an anatomical feature of a patient with respect to arobot arm of a surgical robot, according to some embodiments. In thisexample, data from a plurality of exam image spaces 402, based on aplurality of exam images, may be transformed and combined into a commonexam image space 404. The data from the common exam image space 404 anddata from a verification image space 406, based on a verification image,may be transformed and combined into a registration image space 408.Data from the registration image space 408 may be transformed intopatient fiducial coordinates 410, which is transformed into coordinatesfor a DRB 412. A tracking camera 414 may detect movement of the DRB 412(represented by DRB 412′) and may also detect a location of a probetracker 416 to track coordinates of the DRB 412 over time. A robotic armtracker 418 determines coordinates for the robot arm based ontransformation data from a Robotics Planning System (RPS) space 420 orsimilar modeling system, and/or transformation data from the trackingcamera 414.

It should be understood that these and other features may be used andcombined in different ways to achieve registration of image space, i.e.,coordinates from image volume, into tracking space, i.e., coordinatesfor use by the surgical robot in real-time. As will be discussed indetail below, these features may include fiducial-based registrationsuch as stereotactic frames with CT localizer, preoperative CT or MRIregistered using intraoperative fluoroscopy, calibrated scannerregistration where any acquired scan's coordinates are pre-calibratedrelative to the tracking space, and/or surface registration using atracked probe, for example.

In one example, FIGS. 5A-5C illustrate a system 500 for registering ananatomical feature of a patient. In this example, the stereotactic framebase 530 is fixed to an anatomical feature 528 of patient, e.g., thepatient's head. As shown by FIG. 5A, the stereotactic frame base 530 maybe affixed to the patient's head 528 prior to registration using pinsclamping the skull or other method. The stereotactic frame base 530 mayact as both a fixation platform, for holding the patient's head 528 in afixed position, and registration and tracking platform, foralternatingly holding the CT localizer 536 or the FRA fixture 534. TheCT localizer 536 includes a plurality of fiducial markers 532 (e.g.,N-pattern radio-opaque rods or other fiducials), which are automaticallydetected in the image space using image processing. Due to the preciseattachment mechanism of the CT localizer 536 to the base 530, thesefiducial markers 532 are in known space relative to the stereotacticframe base 530. A 3D CT scan of the patient with CT localizer 536attached is taken, with an image volume that includes both the patient'shead 528 and the fiducial markers 532 of the CT localizer 536. Thisregistration image can be taken intraoperatively or preoperatively,either in the operating room or in radiology, for example. The captured3D image dataset is stored to computer memory.

As shown by FIG. 5B, after the registration image is captured, the CTlocalizer 536 is removed from the stereotactic frame base 530 and theframe reference array fixture 534 is attached to the stereotactic framebase 530. The stereotactic frame base 530 remains fixed to the patient'shead 528, however, and is used to secure the patient during surgery, andserves as the attachment point of a frame reference array fixture 534.The frame reference array fixture 534 includes a frame reference array(FRA), which is a rigid array of three or more tracked markers 539,which may be the primary reference for optical tracking. By positioningthe tracked markers 539 of the FRA in a fixed, known location andorientation relative to the stereotactic frame base 530, the positionand orientation of the patient's head 528 may be tracked in real time.Mount points on the FRA fixture 534 and stereotactic frame base 530 maybe designed such that the FRA fixture 534 attaches reproducibly to thestereotactic frame base 530 with minimal (i.e., submillimetric)variability. These mount points on the stereotactic frame base 530 canbe the same mount points used by the CT localizer 536, which is removedafter the scan has been taken. An auxiliary arm (such as auxiliary arm107 of FIG. 1B, for example) or other attachment mechanism can also beused to securely affix the patient to the robot base to ensure that therobot base is not allowed to move relative to the patient.

As shown by FIG. 5C, a dynamic reference base (DRB) 540 may also beattached to the stereotactic frame base 530. The DRB 540 in this exampleincludes a rigid array of three or more tracked markers 542. In thisexample, the DRB 540 and/or other tracked markers may be attached to thestereotactic frame base 530 and/or to directly to the patient's head 528using auxiliary mounting arms 541, pins, or other attachment mechanisms.Unlike the FRA fixture 534, which mounts in only one way for unambiguouslocalization of the stereotactic frame base 530, the DRB 540 in generalmay be attached as needed for allowing unhindered surgical and equipmentaccess. Once the DRB 540 and FRA fixture 534 are attached, registration,which was initially related to the tracking markers 539 of the FRA, canbe optionally transferred or related to the tracking markers 542 of theDRB 540. For example, if any part of the FRA fixture 534 blocks surgicalaccess, the surgeon may remove the FRA fixture 534 and navigate usingonly the DRB 540. However, if the FRA fixture 534 is not in the way ofthe surgery, the surgeon could opt to navigate from the FRA markers 539,without using a DRB 540, or may navigate using both the FRA markers 539and the DRB 540. In this example, the FRA fixture 534 and/or DRB 540uses optical markers, the tracked positions of which are in knownlocations relative to the stereotactic frame base 530, similar to the CTlocalizer 536, but it should be understood that many other additionaland/or alternative techniques may be used.

FIGS. 6A and 6B illustrate a system 600 for registering an anatomicalfeature of a patient using fluoroscopy (fluoro) imaging, according tosome embodiments. In this embodiment, image space is registered totracking space using multiple intraoperative fluoroscopy (fluoro) imagestaken using a tracked registration fixture 644. The anatomical featureof the patient (e.g., the patient's head 628) is positioned and rigidlyaffixed in a clamping apparatus 643 in a static position for theremainder of the procedure. The clamping apparatus 643 for rigid patientfixation can be a three-pin fixation system such as a Mayfield clamp, astereotactic frame base attached to the surgical table, or anotherfixation method, as desired. The clamping apparatus 643 may alsofunction as a support structure for a patient tracking array or DRB 640as well. The DRB may be attached to the clamping apparatus usingauxiliary mounting arms 641 or other means.

Once the patient is positioned, the fluoro fixture 644 is attached thefluoro unit's x-ray collecting image intensifier (not shown) and securedby tightening clamping feet 632. The fluoro fixture 644 containsfiducial markers (e.g., metal spheres laid out across two planes in thisexample, not shown) that are visible on 2D fluoro images captured by thefluoro image capture device and can be used to calculate the location ofthe x-ray source relative to the image intensifier, which is typicallyabout 1 meter away contralateral to the patient, using a standardpinhole camera model. Detection of the metal spheres in the fluoro imagecaptured by the fluoro image capture device also enables the software tode-warp the fluoro image (i.e., to remove pincushion and s-distortion).Additionally, the fluoro fixture 644 contains 3 or more tracking markers646 for determining the location and orientation of the fluoro fixture644 in tracking space. In some embodiments, software can project vectorsthrough a CT image volume, based on a previously captured CT image, togenerate synthetic images based on contrast levels in the CT image thatappear similar to the actual fluoro images (i.e., digitallyreconstructed radiographs (DRRs)). By iterating through theoreticalpositions of the fluoro beam until the DRRs match the actual fluoroshots, a match can be found between fluoro image and DRR in two or moreperspectives, and based on this match, the location of the patient'shead 628 relative to the x-ray source and detector is calculated.Because the tracking markers 646 on the fluoro fixture 644 track theposition of the image intensifier and the position of the x-ray sourcerelative to the image intensifier is calculated from metal fiducials onthe fluoro fixture 644 projected on 2D images, the position of the x-raysource and detector in tracking space are known and the system is ableto achieve image-to-tracking registration.

As shown by FIGS. 6A and 6B, two or more shots are taken of the head 628of the patient by the fluoro image capture device from two differentperspectives while tracking the array markers 642 of the DRB 640, whichis fixed to the registration fixture 630 via a mounting arm 641, andtracking markers 646 on the fluoro fixture 644. Based on the trackingdata and fluoro data, an algorithm computes the location of the head 628or other anatomical feature relative to the tracking space for theprocedure. Through image-to-tracking registration, the location of anytracked tool in the image volume space can be calculated.

For example, in one embodiment, a first fluoro image taken from a firstfluoro perspective can be compared to a first DRR constructed from afirst perspective through a CT image volume, and a second fluoro imagetaken from a second fluoro perspective can be compared to a second DRRconstructed from a second perspective through the same CT image volume.Based on the comparisons, it may be determined that the first DRR issubstantially equivalent to the first fluoro image with respect to theprojected view of the anatomical feature, and that the second DRR issubstantially equivalent to the second fluoro image with respect to theprojected view of the anatomical feature. Equivalency confirms that theposition and orientation of the x-ray path from emitter to collector onthe actual fluoro machine as tracked in camera space matches theposition and orientation of the x-ray path from emitter to collector asspecified when generating the DRRs in CT space, and thereforeregistration of tracking space to CT space is achieved.

FIG. 7 illustrates a system 700 for registering an anatomical feature ofa patient using an intraoperative CT fixture (ICT) and a DRB, accordingto some embodiments. As shown in FIG. 7, in one application, afiducial-based image-to-tracking registration can be utilized that usesan intraoperative CT fixture (ICT) 750 having a plurality of trackingmarkers 751 and radio-opaque fiducial reference markers 732 to registerthe CT space to the tracking space. After stabilizing the anatomicalfeature 728 (e.g., the patient's head) using clamping apparatus 730 suchas a three-pin Mayfield frame and/or stereotactic frame, the surgeonwill affix the ICT 750 to the anatomical feature 728, DRB 740, orclamping apparatus 730, so that it is in a static position relative tothe tracking markers 742 of the DRB 740, which may be held in place bymounting arm 741 or other rigid means. A CT scan is captured thatencompasses the fiducial reference markers 732 of the ICT 750 while alsocapturing relevant anatomy of the anatomical feature 728. Once the CTscan is loaded in the software, the system auto-identifies (throughimage processing) locations of the fiducial reference markers 732 of theICT within the CT volume, which are in a fixed position relative to thetracking markers of the ICT 750, providing image-to-trackingregistration. This registration, which was initially based on thetracking markers 751 of the ICT 750, is then related to or transferredto the tracking markers 742 of the DRB 740, and the ICT 750 may then beremoved.

FIG. 8A illustrates a system 800 for registering an anatomical featureof a patient using a DRB and an X-ray cone beam imaging device,according to some embodiments. An intraoperative scanner 852, such as anX-ray machine or other scanning device, may have a tracking array 854with tracking markers 855, mounted thereon for registration. Based onthe fixed, known position of the tracking array 854 on the scanningdevice, the system may be calibrated to directly map (register) thetracking space to the image space of any scan acquired by the system.Once registration is achieved, the registration, which is initiallybased on the tracking markers 855 (e.g. gantry markers) of the scanner'sarray 854, is related or transferred to the tracking markers 842 of aDRB 840, which may be fixed to a clamping fixture 830 holding thepatient's head 828 by a mounting arm 841 or other rigid means. Aftertransferring registration, the markers on the scanner are no longer usedand can be removed, deactivated or covered if desired. Registering thetracking space to any image acquired by a scanner in this way may avoidthe need for fiducials or other reference markers in the image space insome embodiments.

FIG. 8B illustrates an alternative system 800′ that uses a portableintraoperative scanner, referred to herein as a C-arm scanner 853. Inthis example, the C-arm scanner 853 includes a c-shaped arm 856 coupledto a movable base 858 to allow the C-arm scanner 853 to be moved intoplace and removed as needed, without interfering with other aspects ofthe surgery. The arm 856 is positioned around the patient's head 828intraoperatively, and the arm 856 is rotated and/or translated withrespect to the patient's head 828 to capture the X-ray or other type ofscan that to achieve registration, at which point the C-arm scanner 853may be removed from the patient.

Another registration method for an anatomical feature of a patient,e.g., a patient's head, may be to use a surface contour map of theanatomical feature, according to some embodiments. A surface contour mapmay be constructed using a navigated or tracked probe, or othermeasuring or sensing device, such as a laser pointer, 3D camera, etc.For example, a surgeon may drag or sequentially touch points on thesurface of the head with the navigated probe to capture the surfaceacross unique protrusions, such as zygomatic bones, superciliary arches,bridge of nose, eyebrows, etc. The system then compares the resultingsurface contours to contours detected from the CT and/or MR images,seeking the location and orientation of contour that provides theclosest match. To account for movement of the patient and to ensure thatall contour points are taken relative to the same anatomical feature,each contour point is related to tracking markers on a DRB on thepatient at the time it is recorded. Since the location of the contourmap is known in tracking space from the tracked probe and tracked DRB,tracking-to-image registration is obtained once the correspondingcontour is found in image space.

FIG. 9 illustrates a system 900 for registering an anatomical feature ofa patient using a navigated or tracked probe and fiducials forpoint-to-point mapping of the anatomical feature 928 (e.g., a patient'shead), according to some embodiments. Software would instruct the userto point with a tracked probe to a series of anatomical landmark pointsthat can be found in the CT or MR image. When the user points to thelandmark indicated by software, the system captures a frame of trackingdata with the tracked locations of tracking markers on the probe and onthe DRB. From the tracked locations of markers on the probe, thecoordinates of the tip of the probe are calculated and related to thelocations of markers on the DRB. Once 3 or more points are found in bothspaces, tracking-to-image registration is achieved. As an alternative topointing to natural anatomical landmarks, fiducials 954 (i.e., fiducialmarkers), such as sticker fiducials or metal fiducials, may be used. Thesurgeon will attach the fiducials 954 to the patient, which areconstructed of material that is opaque on imaging, for examplecontaining metal if used with CT or Vitamin E if used with MR. Imaging(CT or MR) will occur after placing the fiducials 954. The surgeon oruser will then manually find the coordinates of the fiducials in theimage volume, or the software will find them automatically with imageprocessing. After attaching a DRB 940 with tracking markers 942 to thepatient through a mounting arm 941 connected to a clamping apparatus 930or other rigid means, the surgeon or user may also locate the fiducials954 in physical space relative to the DRB 940 by touching the fiducials954 with a tracked probe while simultaneously recording tracking markerson the probe (not shown) and on the DRB 940. Registration is achievedbecause the coordinates of the same points are known in the image spaceand the tracking space.

One use for the embodiments described herein is to plan trajectories andto control a robot to move into a desired trajectory, after which thesurgeon will place implants such as electrodes through a guide tube heldby the robot. Additional functionalities include exporting coordinatesused with existing stereotactic frames, such as a Leksell frame, whichuses five coordinates: X, Y, Z, Ring Angle and Arc Angle. These fivecoordinates are established using the target and trajectory identifiedin the planning stage relative to the image space and knowing theposition and orientation of the ring and arc relative to thestereotactic frame base or other registration fixture.

As shown in FIG. 10, stereotactic frames allow a target location 1058 ofan anatomical feature 1028 (e.g., a patient's head) to be treated as thecenter of a sphere and the trajectory can pivot about the targetlocation 1058. The trajectory to the target location 1058 is adjusted bythe ring and arc angles of the stereotactic frame (e.g., a Leksellframe). These coordinates may be set manually, and the stereotacticframe may be used as a backup or as a redundant system in case the robotfails or cannot be tracked or registered successfully. The linear x,y,zoffsets to the center point (i.e., target location 1058) are adjustedvia the mechanisms of the frame. A cone 1060 is centered around thetarget location 1058, and shows the adjustment zone that can be achievedby modifying the ring and arc angles of the Leksell or other type offrame. This figure illustrates that a stereotactic frame with ring andarc adjustments is well suited for reaching a fixed target location froma range of angles while changing the entry point into the skull.

FIG. 11 illustrates a two-dimensional visualization of virtual pointrotation mechanism, according to some embodiments. In this embodiment,the robotic arm is able to create a different type of point-rotationfunctionality that enables a new movement mode that is not easilyachievable with a 5-axis mechanical frame, but that may be achievedusing the embodiments described herein. Through coordinated control ofthe robot's axes using the registration techniques described herein,this mode allows the user to pivot the robot's guide tube about anyfixed point in space. For example, the robot may pivot about the entrypoint 1162 into the anatomical feature 1128 (e.g., a patient's head).This entry point pivoting is advantageous as it allows the user to makea smaller burr hole without limiting their ability to adjust the targetlocation 1164 intraoperatively. The cone 1160 represents the range oftrajectories that may be reachable through a single entry hole.Additionally, entry point pivoting is advantageous as it allows the userto reach two different target locations 1164 and 1166 through the samesmall entry burr hole. Alternately, the robot may pivot about a targetpoint (e.g., location 1058 shown in FIG. 10) within the skull to reachthe target location from different angles or trajectories, asillustrated in FIG. 10. Such interior pivoting robotically has the sameadvantages as a stereotactic frame as it allows the user to approach thesame target location 1058 from multiple approaches, such as whenirradiating a tumor or when adjusting a path so that critical structuressuch as blood vessels or nerves will not be crossed when reachingtargets beyond them. Unlike a stereotactic frame, which relies on fixedring and arc articulations to keep a target/pivot point fixed, the robotadjusts the pivot point through controlled activation of axes and therobot can therefore dynamically adjust its pivot point and switch asneeded between the modes illustrated in FIGS. 10 and 11.

Following the insertion of implants or instrumentation using the robotor ring and arc fixture, these and other embodiments may allow forimplant locations to be verified using intraoperative imaging. Placementaccuracy of the instrument or implant relative to the planned trajectorycan be qualitatively and/or quantitatively shown to the user. One optionfor comparing planned to placed position is to merge a postoperativeverification CT image to any of the preoperative images. Once pre- andpost-operative images are merged and plan is shown overlaid, the shadowof the implant on postop CT can be compared to the plan to assessaccuracy of placement. Detection of the shadow artifact on post-op CTcan be performed automatically through image processing and the offsetdisplayed numerically in terms of millimeters offset at the tip andentry and angular offset along the path. This option does not requireany fiducials to be present in the verification image sinceimage-to-image registration is performed based on bony anatomicalcontours.

A second option for comparing planned position to the final placementwould utilize intraoperative fluoro with or without an attached fluorofixture. Two out-of-plane fluoro images will be taken and these fluoroimages will be matched to DRRs generated from pre-operative CT or MR asdescribed above for registration. Unlike some of the registrationmethods described above, however, it may be less important for thefluoro images to be tracked because the key information is where theelectrode is located relative to the anatomy in the fluoro image. Thelinear or slightly curved shadow of the electrode would be found on afluoro image, and once the DRR corresponding to that fluoro shot isfound, this shadow can be replicated in the CT image volume as a planeor sheet that is oriented in and out of the ray direction of the fluoroimage and DRR. That is, the system may not know how deep in or out ofthe fluoro image plane the electrode lies on a given shot, but cancalculate the plane or sheet of possible locations and represent thisplane or sheet on the 3D volume. In a second fluoro view, a differentplane or sheet can be determined and overlaid on the 3D image. Wherethese two planes or sheets intersect on the 3D image is the detectedpath of the electrode. The system can represent this detected path as agraphic on the 3D image volume and allow the user to reslice the imagevolume to display this path and the planned path from whateverperspective is desired, also allowing automatic or manual calculation ofthe deviation from planned to placed position of the electrode. Trackingthe fluoro fixture is unnecessary but may be done to help de-warp thefluoro images and calculate the location of the x-ray emitter to improveaccuracy of DRR calculation, the rate of convergence when iterating tofind matching DRR and fluoro shots, and placement of sheets/planesrepresenting the electrode on the 3D scan.

In this and other examples, it is desirable to maintain navigationintegrity, i.e., to ensure that the registration and tracking remainaccurate throughout the procedure. Two primary methods to establish andmaintain navigation integrity include: tracking the position of asurveillance marker relative to the markers on the DRB, and checkinglandmarks within the images. In the first method, should this positionchange due to, for example, the DRB being bumped, then the system mayalert the user of a possible loss of navigation integrity. In the secondmethod, if a landmark check shows that the anatomy represented in thedisplayed slices on screen does not match the anatomy at which the tipof the probe points, then the surgeon will also become aware that thereis a loss of navigation integrity. In either method, if using theregistration method of CT localizer and frame reference array (FRA), thesurgeon has the option to re-attach the FRA, which mounts in only onepossible way to the frame base, and to restore tracking-to-imageregistration based on the FRA tracking markers and the stored fiducialsfrom the CT localizer 536. This registration can then be transferred orrelated to tracking markers on a repositioned DRB. Once registration istransferred the FRA can be removed if desired.

Referring now to FIGS. 12-18 generally, with reference to the surgicalrobot system 100 shown in FIG. 1A, end-effector 112 may be equipped withcomponents, configured, or otherwise include features so that oneend-effector may remain attached to a given one of robot arms 104without changing to another end-effector for multiple different surgicalprocedures, such as, by way of example only, Deep Brain Stimulation(DBS), Stereoelectroencephalography (SEEG), or Endoscopic Navigation andTumor Biopsy. As discussed previously, end-effector 112 may beorientable to oppose an anatomical feature of a patient in the manner soas to be in operative proximity thereto, and, to be able to receive oneor more surgical tools for operations contemplated on the anatomicalfeature proximate to the end-effector 112. Motion and orientation ofend-effector 112 may be accomplished through any of the navigation,trajectory guidance, or other methodologies discussed herein or as maybe otherwise suitable for the particular operation.

End-effector 112 is suitably configured to permit a plurality ofsurgical tools 129 to be selectively connectable to end-effector 112.Thus, for example, a stylet 113 (FIG. 13) may be selectively attached inorder to localize an incision point on an anatomical feature of apatient, or an electrode driver 115 (FIG. 14) may be selectivelyattached to the same end-effector 112.

With reference to the previous discussion of robot surgical system 100,a processor circuit, as well as memory accessible by such processorcircuit, includes various subroutines and other machine-readableinstructions configured to cause, when executed, end-effector 112 tomove, such as by GPS movement, relative to the anatomical feature, atpredetermined stages of associated surgical operations, whetherpre-operative, intra-operative or post-operative.

End-effector 112 includes various components and features to eitherprevent or permit end-effector movement depending on whether and whichtools 129, if any, are connected to end-effector 112. Referring moreparticularly to FIG. 12, end-effector 112 includes a tool-insert lockingmechanism 117 located on and connected to proximal surface 119.Tool-insert locking mechanism 117 is configured so as to secure anyselected one of a plurality of surgical tools, such as the aforesaidstylet 113, electrode driver 115, or any other tools for differentsurgeries mentioned previously or as may be contemplated by otherapplications of this disclosure. The securement of the tool bytool-insert locking mechanism 117 is such that, for any of multipletools capable of being secured to locking mechanism 117, each such toolis operatively and suitably secured at the predetermined height, angleof orientation, and rotational position relative to the anatomicalfeature of the patient, such that multiple tools may be secured to thesame end-effector 112 in respective positions appropriate for thecontemplated procedure.

Another feature of the end-effector 112 is a tool stop 121 located ondistal surface 123 of end-effector 112, that is, the surface generallyopposing the patient. Tool stop 121 has a stop mechanism 125 and asensor 127 operatively associated therewith, as seen with reference toFIGS. 16, 19, and 20. Stop mechanism 125 is mounted to end-effector 112so as to be selectively movable relative thereto between an engagedposition to prevent any of the tools from being connected toend-effector 112 and a disengaged position which permits any of thetools 129 to be selectively connected to end-effector 112. Sensor 127may be located on or within the housing of end-effector 112 at anysuitable location (FIGS. 12, 14, 16) so that sensor 127 detects whetherstop mechanism 125 is in the engaged or disengaged position. Sensor 127may assume any form suitable for such detection, such as any type ofmechanical switch or any type of magnetic sensor, including Reedswitches, Hall Effect sensors, or other magnetic field detectingdevices. In one possible implementation, sensor 127 has two portions, aHall Effect sensor portion (not shown) and a magnetic portion 131, thetwo portions moving relative to each other so as to generate and detecttwo magnetic fields corresponding to respective engaged and disengagedposition. In the illustrated implementation, the magnetic portioncomprises two rare earth magnets 131 which move relative to thecomplementary sensing portion (not shown) mounted in the housing of endeffector 112 in operative proximity to magnets 131 to detect change inthe associated magnetic field from movement of stop mechanism 125between engaged and disengaged positions. In this implementation theHall Effect sensor is bipolar and can detect whether a North pole orSouth pole of a magnet opposes the sensor. Magnets 131 are configured sothat the North pole of one magnet faces the path of the sensor and theSouth pole of the other magnet faces the path of the sensor. In thisconfiguration, the sensor senses an increased signal when it is near onemagnet (for example, in disengaged position), a decreased signal when itis near the other magnet (for example, in engaged position), andunchanged signal when it is not in proximity to any magnet. In thisimplementation, in response to detection of stop mechanism 125 being inthe disengaged position shown in FIGS. 13 and 19, sensor 127 causes theprocessor of surgical robot system 100 to execute suitable instructionsto prevent movement of end-effector 112 relative to the anatomicalfeature. Such movement prevention may be appropriate for any number ofreasons, such as when a tool is connected to end-effector 112, such toolpotentially interacting with the anatomical feature of the patient.

Another implementation of a sensor 127 for detecting engaged ordisengaged tool stop mechanism 125 could comprise a single magnet behindthe housing (not shown) and two Hall Effect sensors located wheremagnets 131 are shown in the preferred embodiment. In such aconfiguration, monopolar Hall Effect sensors are suitable and would beconfigured so that Sensor 1 detects a signal when the magnet is inproximity due to the locking mechanism being disengaged, while Sensor 2detects a signal when the same magnet is in proximity due to the lockingmechanism being engaged. Neither sensor would detect a signal when themagnet is between positions or out of proximity to either sensor.Although a configuration could be conceived in which a sensor is activefor engaged position and inactive for disengaged position, aconfiguration with three signals indicating engaged, disengaged, ortransitional is preferred to ensure correct behavior in case of powerfailure.

End-effector 112, tool stop 121, and tool-insert locking mechanism 117each have co-axially aligned bores or apertures such that any selectedone of the plurality of surgical tools 129 may be received through suchbores and apertures. In this implementation end-effector has a bore 133and tool stop 121 and tool-insert locking mechanism 117 have respectiveapertures 135 and 137. Stop mechanism 125 includes a ring 139 axiallyaligned with bore 133 and aperture 135 of tool stop 121. Ring 139 isselectively, manually rotatable in the directions indicated by arrow A(FIG. 16) so as to move stop mechanism 125 between the engaged positionand the disengaged position.

In one possible implementation, the selective rotation of ring 139includes features which enable ring 139 to be locked in either thedisengaged or engaged position. So, for example, as illustrated, adetent mechanism 141 is located on and mounted to ring 139 in anysuitable way to lock ring 139 against certain rotational movement out ofa predetermined position, in this case, such position being when stopmechanism 125 is in the engaged position. Although various forms ofdetent mechanism are contemplated herein, one suitable arrangement has amanually accessible head extending circumferentially outwardly from ring139 and having a male protrusion (not shown) spring-loaded axiallyinwardly to engage a corresponding female detent portion (not shown).Detent mechanism 141, as such, is manually actuatable to unlock ring 139from its engaged position to permit ring 139 to be manually rotated tocause stop mechanism 125 to move from the engaged position (FIG. 20) tothe disengaged position (FIG. 19).

Tool stop 121 includes a lever arm 143 pivotally mounted adjacentaperture 135 of tool stop 121 so end of lever arm 143 selectively pivotsin the directions indicated by arrow B (FIGS. 16, 19 and 20). Lever arm143 is operatively connected to stop mechanism 125, meaning it closesaperture 135 of tool stop 121 in response to stop mechanism 125 being inthe engaged position, as shown in FIG. 20. Lever arm 143 is alsooperatively connected so as to pivot back in direction of arrow B toopen aperture 135 in response to stop mechanism 125 being in thedisengaged position. As such, movement of stop mechanism 125 betweenengaged and disengaged positions results in closure or opening ofaperture 135, respectively, by lever arm 143.

Lever arm 143, in this implementation, is not only pivotally mountedadjacent aperture 135, but also pivots in parallel with a distal planedefined at a distal-most point of distal surface 123 of end-effector112. In this manner, any one of the surgical tools 129, which isattempted to be inserted through bore 133 and aperture 135, is stoppedfrom being inserted past the distal plane in which lever arm 143 rotatesto close aperture 135.

Turning now to tool-insert locking mechanism 117 (FIG. 13, 17, 18), aconnector 145 is configured to meet with and secure any one of thesurgical tools 129 at their appropriate height, angle of orientation,and rotational position relative to the anatomical feature of thepatient. In the illustrated implementation, connector 145 comprises arotatable flange 147 which has at least one slot 149 formed therein toreceive there through a corresponding tongue 151 associated with aselected one of the plurality of tools 129. So, for example, in FIG. 14,the particular electrode driver 115 has multiple tongues, one of whichtongue 151 is shown. Rotatable flange 147, in some implementations, maycomprise a collar 153, which collar, in turn, has multiple ones of slots149 radially spaced on a proximally oriented surface 155, as best seenin FIG. 12. Multiple slots 147 arranged around collar 153 are sized orotherwise configured so as to receive there through corresponding onesof multiple tongues 151 associated with a selected one of the pluralityof tools 129. Therefore, as seen in FIG. 13, multiple slots 149 andcorresponding tongues 151 may be arranged to permit securing of aselected one of the plurality of tools 129 only when selected tool is inthe correct, predetermined angle of orientation and rotational positionrelative to the anatomical feature of the patient. Similarly, withregard to the electrode driver shown in FIG. 14, tongues 151 (one ofwhich is shown in a cutaway of FIG. 14) have been received in radiallyspaced slots 149 arrayed so that electrode driver 115 is received at theappropriate angle of orientation and rotational position.

Rotatable flange 147 has, in this implementation, a grip 173 tofacilitate manual rotation between an open and closed position as shownin FIGS. 17 and 18, respectively. As seen in FIG. 17, multiple sets ofmating slots 149 and tongues 151 are arranged at different angularlocations, in this case, locations which may be symmetric about a singlediametric chord of a circle but otherwise radially asymmetric, and atleast one of the slots has a different dimension or extends through adifferent arc length than other slots. In this slot-tongue arrangement,and any number of variations contemplated by this disclosure, there isonly one rotational position of the tool 129 (or adapter 155 discussedlater) to be received in tool-insert locking mechanism 117 whenrotatable flange 147 is in the open position shown in FIG. 17. In otherwords, when the user of system 100 moves a selected tool 129 (or tooladapter 155) to a single appropriate rotational position, correspondingtongues 151 may be received through slots 149. Upon placement of tongues151 into slots 149, tongues 151 confront a base surface 175 withinconnector 145 of rotatable flange 147. Upon receiving tongues 151 intoslots 149 and having them rest on underlying base surface 175,dimensions of tongues 151 and slots 149, especially with regard toheight relative to rotatable flange 147, are selected so that whenrotatable flange 147 is rotated to the closed position, flange portions157 are radially translated to overlie or engage portions of tongues151, such engagement shown in FIG. 18 and affixing tool 129 (or adapter155) received in connector 145 at the desired, predetermined height,angle of orientation, and rotational position relative to the anatomicalfeature of the patient.

Tongues 151 described as being associated with tools 129 may either bedirectly connected to such tools 129, and/or tongues 151 may be locatedon and mounted to the above-mentioned adapter 155, such as that shown inFIGS. 12, 17 and 18, such adapter 155 configured to interconnect atleast one of the plurality of surgical tools 129 with end-effector 112.In the described implementation, adapter 155 includes two operativeportions—a tool receiver 157 adapted to connect the selected one or moresurgical tools 129, and the second operative part being one or moretongues 151 which may, in this implementation, be mounted and connectedto the distal end of adapter 155.

Adapter 155 has an outer perimeter 159 which, in this implementation, issized to oppose an inner perimeter 161 of rotatable flange 147. Adapter155 extends between proximal and distal ends 163, 165, respectively andhas an adapter bore 167 extending between ends 163, 165. Adapter bore167 is sized to receive at least one of the plurality of surgical tools129, and similarly, the distance between proximal and distal ends 163,165 is selected so that at least one of tools 129 is secured toend-effector 112 at the predetermined, appropriate height for thesurgical procedure associated with such tool received in adapter bore167.

In one possible implementation, system 100 includes multiple ones ofadapter 155, configured to be interchangeable inserts 169 havingsubstantially the same, predetermined outer perimeters 159 to bereceived within inner perimeter 161 of rotatable flange 147. Stillfurther in such implementation, the interchangeable inserts 169 havebores of different, respective diameters, which bores may be selected toreceive corresponding ones of the tools 129 therein. Bores 167 maycomprise cylindrical bushings having inner diameters common to multiplesurgical tools 129. One possible set of diameters for bores 167 may be12, 15, and 17 millimeters, suitable for multiple robotic surgeryoperations, such as those identified in this disclosure.

In the illustrated implementation, inner perimeter 161 of rotatableflange 147 and outer perimeter 159 of adapter 155 are circular, havingcentral, aligned axes and corresponding radii. Slots 149 of rotatableflange 147 extend radially outwardly from the central axis of rotatableflange 147 in the illustrated implementation, whereas tongues 151 ofadapter 155 extend radially outwardly from adapter 155.

In still other implementations, end-effector 112 may be equipped with atleast one illumination element 171 (FIGS. 14 and 15) orientable towardthe anatomical feature to be operated upon. Illumination element 171 maybe in the form of a ring of LEDs 177 (FIG. 14) located within adapter167, which adapter is in the form of a bushing secured to tool lockingmechanism 117. Illumination element 171 may also be a single LED 179mounted on the distal surface 123 of end-effector 112. Whether in theform of LED ring 177 or a single element LED 179 mounted on distalsurface of end-effector 112, or any other variation, the spacing andlocation of illumination element or elements 171 may be selected so thattools 129 received through bore 133 of end-effector 112 do not castshadows or otherwise interfere with illumination from element 171 of theanatomical feature being operated upon.

The operation and associated features of end-effector 112 are readilyapparent from the foregoing description. Tool stop 121 is rotatable,selectively lockable, and movable between engaged and disengagedpositions, and a sensor prevents movement of end-effector 112 when insuch disengaged position, due to the potential presence of a tool whichmay not be advisably moved during such disengaged position. Tool-insertlocking mechanism 117 is likewise rotatable between open and closedpositions to receive one of a plurality of interchangeable inserts 169and tongues 151 of such inserts, wherein selected tools 129 may bereceived in such inserts 169; alternately, tongues 151 may be otherwiseassociated with tools 129, such as by having tongues 151 directlyconnected to such tools 129, which tongue-equipped tools likewise may bereceived in corresponding slots 149 of tool-insert locking mechanism117. Tool-insert locking mechanism 117 may be rotated from its openposition in which tongues 151 have been received in slots 149, to secureassociated adapters 155 and/or tools 129 so that they are atappropriate, respective heights, angles of orientation, and rotationalpositions relative to the anatomical feature of the patient.

For those implementations with multiple adapters 155, the dimensions ofsuch adapters 155, including bore diameters, height, and other suitabledimensions, are selected so that a single or a minimized number ofend-effectors 112 can be used for a multiplicity of surgical tools 129.Adapters 155, such as those in the form of interchangeable inserts 169or cylindrical bushings, may facilitate connecting an expanded set ofsurgical tools 129 to the end-effector 112, and thus likewise facilitatea corresponding expanded set of associated surgical features using thesame end-effector 112.

FIGS. 21 and 22 illustrate in schematic form yet another possibleimplementation of a robot system 100 as hereinbefore described, withlike reference numbers referring to like components. In thisimplementation, surgical robot system 100 includes features for drillinga hole or bore in a cranium of a head 128 (FIG. 2) of a patient 210(FIG. 1B), such as in connection with cranial surgery. Surgical robotsystem 100 includes some or all of the various features andfunctionalities discussed with reference to the previous embodiments,including, for example, a surgical robot 102, robot arm 104 connected tosurgical robot 102 and an end-effector 112 connected to robot arm 104and orientable to oppose the cranium of the patient 210 (FIG. 1B), suchend-effector 112 thereby being in sufficient proximity to perform thecontemplated operation.

One of the surgical tools 129 suitable for use with end-effector 112 isa perforator 222 connectable to end-effector 112. Perforator 222 isshown schematically in this disclosure, for purposes of illustrating itsconical oscillations and other related operations and features.Accordingly, it will be appreciated that the dimensions of theperforator 222 are not to scale, and that the diameter of perforator222, as well as the perforator bit and perforator tip discussed hereinare often larger than as illustrated in FIGS. 21 and 22, both inabsolute terms and also relative to other features shown. Similarly,perforator length and other dimensions of those of components associatedwith perforator 222, may likewise vary, depending on the application.For certain cranial applications, perforator bit diameters ranging from1 cm to 3 cm have been found suitable, and still other diameters arecontemplated within the scope and spirit of this disclosure.

End-effector 112, in certain implementations, may comprise a robot wrist226 or a similar arrangement of moveable components so that theperforator 222 is connectable to end-effector 112 and configured to beadvanced or withdrawn along a trajectory line L relative to the craniumof patient's head 128. Perforator 222 has an elongated perforator bit224 terminating in a sharp perforator tip 228. Perforator bit 224 has acorresponding bit diameter as well as an internal mechanical clutch (notshown) operable to selectively engage or disengage rotation of bit 224so as to drill a bore in a cranium for contemplated surgical procedures,including any number of craniotomies, such as DBS electrode placementand other associated operations associated with cranial surgery. Theclutch mechanism is spring-loaded longitudinally, so that the springforces interfacing portions apart from each other when there is noforward force present opposing the bit. With the clutch mechanismseparated, although the inner shaft of the drill continues to spin, thebit is not engaged and does not spin. With forward thrustinglongitudinal force, as the spring is overcome, the portions of theclutch mechanism are forced together, allowing the rotating shaft toengage the bit and cause the bit to rotate with the shaft.

In one suitable mode of operation, clutch engages and rotates bit 224 asinterfacing portions of the clutch are forced together by resistance orsimilar opposing or reactive force during advancement of bit 224, andclutch disengages rotation when interfacing portions move apart afterthe leading edge of the bit penetrates past an internal wall of thecranium, such penetration associated with insufficient force to keep theportions of the clutch engaged.

Certain operations of perforator 222 may be performed manually, such asmanual advancement or withdrawal of perforator bit 224 relative to thecranium. This and other operations may be performed by various computerimplementations, including a processor circuit associated with suchcomputerized implementation, a memory accessible by the processorcircuit and comprising machine-readable instructions for performingvarious steps associated with perforator 222.

In one possible implementation, the machine-readable instructions, whenexecuted, cause perforator 222 not only to maintain perforator tip 228along the trajectory line L during advancement of bit 224 toward thecranium, but they further cause the perforator bit to move in a conicaloscillation relative to trajectory line L. FIG. 21 shows such conicaloscillation movement at one point during the orbiting of perforator bit224 about trajectory line L, this conical motion evident with theleading tip of the perforator coincident with line L while the trailingend of the perforator is slightly offset from line L, such orbiting andthe associated advancement being accomplished by suitablemachine-readable instructions for moving robot arm 104, and componentscomprising or secured to robot arm 104. Movements to achieve suitableconical oscillation may include computer-directed movements in thedirections of arrows A, B, and C.

As a result of moving perforator bit 224 in a conical oscillation whilealso advancing it through the cranium, the bore formed in the cranium isgenerally circular and has a diameter larger than the bore diameterwhich would have been formed without such conical oscillation movementduring advancement of the perforator tip. As such, a bore is formed inthe cranium having a diameter not only larger than the bit diameter, butthe oscillation is selected so that the resulting bore of largerdiameter reduces frictional force which might otherwise opposewithdrawal of perforator bit 224 from the bore formed in the craniumafter penetration of the inner wall of such cranium. Such frictionalforce is otherwise associated with jamming of the perforator bit 224 inthe cranium and therefore the larger bore accomplished by conicaloscillation reduces the risk of such jamming.

In certain implementations, orienting the perforator bit at an angle Brelative to trajectory line L ranging from about 1° to about 3° has beenfound suitable, and in certain other implementations, an angle β ofabout 2° relative to trajectory line L has been found suitable.

The above-described conical oscillation movement may be initiated,controlled, or otherwise implemented in association with either manualor automatic steps in any number of ways. For example, oscillation maybe imparted by the robotic system 100 including a suitable userinterface and machine-readable instructions corresponding to aperforator mode. As such, the conical oscillation may be initiated,caused or controlled by user selection of such perforator mode throughthe user interface. In other possible implementations, end-effector 112in the form of robot wrist 226 may be advanced by manually moving robotarm 104 or other components associated with advancement of end-effector112 and similarly, withdrawing up trajectory line L after perforation ofthe cranium may be performed manually.

In still other implementations, a load cell 232 may be operativelyconnected to robot wrist 226. Load cell 232 is configured to sensereactive force corresponding to perforator bit 224 engaging the cranium.Load cell 232 likewise is able to detect a reduction in such reactiveforce by a predetermined amount. Such predetermined amount is selectedor corresponds to the drop-off of reactive force corresponding tocompletion of perforation of the cranium. As such, the system 100 mayinclude further machine-readable instructions responsive to the loadcell detecting such reduction in reactive force by the predeterminedamount. One set of instructions in response to detection of reduction inthe reactive force may result in generation of a user perceptible signalor alarm, especially useful if the perforator 222 is being advancedmanually, so that the user may cease manual advancement upon receivingthe signal generated by system 100.

The perforator mode of system 100 may include more automated control ofperforator 222, such that, upon load cell 232 detecting the reduction inreactive force corresponding to completing perforation, the automaticadvancement accomplished by system 100 of perforator 222 isautomatically ceased. Control of advancement and withdraw of theperforator may be further automated so that, upon detection by the loadcell of the requisite reduction in reactive force, not only isadvancement ceased, but the robot arm, wrist, or perforator arewithdrawn along trajectory line L thereafter.

In still another possible variation of control of perforator 222 bysuitable machine-readable instructions, robot wrist 226 may be locatedso as to be accessible to the user and load cell 232 is configured tosense manual application of forward and rearward force to either theend-effector 112, robot arm 102, or robot wrist 226. Such manual forcemay be a tap forward or a tap back. In response to detecting such force,machine-readable instructions may cause perforator 222 to move downtrajectory line L in response to sensing a forward tap and may cause theperforator 222 to be moved up the trajectory line L in response tosensing a rearward tap.

In view of the foregoing, system 100 may, in certain implementationsinclude suitable instructions to inter-relate signals from load cell232, corresponding to the presence and amount of reactive forceexperienced by perforator bit 224 with features of a clutch or motorcontroller 230 with electronic signal inputs related to selectiverotation of perforator bit 224. In this way, system 100 may control notonly advancement or withdrawal of perforator 222 by means of load cell232, but may also interact with or replace clutch 230 to start, stop orvary speed of rotation of perforator bit 224. Such interactions may be afunction of the amount of reactive force sensed by load cell 232,including cessation of such rotation upon fall-off of reactive forcesensed by the load cell 232 by one or more predetermined amounts.

Although the implementations illustrated and described above withreference to FIG. 21 contemplate movement of one or more components ofrobot arm 104 to impart the necessary conical oscillation, it is withinthe spirit and scope of this disclosure to control perforator 222 andits associated conical oscillation by controlled movements of othercomponents of robot 102. For example, in conjunction with robot arm 104or in place thereof, a linear slide 234, as shown in FIG. 22, may beused to impart the desired conical oscillation, as well as to advance orwithdraw perforator 222 and its associated perforator bit 224 during thedrilling of a hole or bore in a cranium.

Linear slide 234 includes inner and outer cylindrical assemblies, whichmay be oriented concentrically so that each cylinder's central axiscorresponds to the directions of advancement and withdrawal alongtrajectory line L. A pair of tracks 236 extends vertically at locationsrelative to trajectory line L and is defined in circular members 238approximately 180 degrees from each other. The inner cylindricalassembly includes a ring 240 with tongues slideably received withingrooves 236. Radially inwardly from ring 240, a bracket 244 is connectedto a guide tube 248 within which perforator 222 is suitably connected. Arotary bearing 242 rotatably connects bracket 244 to ring 240. Themovement vertically of ring 240 relative to grooves 236 corresponds toadvancement or withdrawal of perforator 222, rotary movement of rotarybearing 242 in a circular fashion corresponds to conical oscillation, asit allows bracket 244 to spin within ring 240 while swivel perforatorbit 224 is held at an angle to bracket 244.

Bracket 244 includes offset slots 246 at upper and lower ends of bracket244. Offset slots 246 provide a track within which cylindrical bumpoutson guide tube 248 move, permitting perforator tip 228 to be maintainedat adjustable positions near or on trajectory line L, while alsoallowing perforator tail end to be positioned at adjustable offsets nearor on trajectory line L that may be different than offsets of perforatortip 228. To that end, the radius of the cone associated with the conicaloscillation may vary depending on the location of guide tube 248 withinbracket 244, and location of perforator bit 224 and perforator tail endrelative to line L.

The operation of linear slide 234 is apparent from the foregoingdescription. The appropriate angle β of perforator bit 224 may be set bymanual or automatic movement of guide tube 248 within offset slots 246.Suitable moveable connections and associated motors are actuatable inresponse to programmable logic controllers and associatedmachine-readable instructions to impart rotation associated with theconical oscillation of perforator bit 224 by rotary bearing 242 beingrotated within ring 240 by suitable instructions and associated rotationmeans. As perforator bit 224 is orbited at its angle β relative totrajectory line L, perforator tip 228 is maintained along trajectoryline L and advanced by relative movement of ring 240 within grooves 236near slide 234.

Alternately, it will be appreciated that linear slide 234 may beadjusted so that guide tube 248 is coaxial with trajectory line L. Suchcoaxial alignment would occur when guide tube 248 is moved to pointswithin offsets 246 corresponding to such axial alignment. In such axialalignment, both rotation and advancement of perforator bit 224 may occurwithout conical oscillation associated therewith. During operations oflinear slide 234, robot wrist 226 and robot arm 104 may remainstationary during all or part of advancement or withdrawal of perforatorbit 224 relative to the cranium and the bore being formed therein.

Operations of the implementations disclosed with reference to FIGS. 21and 22, and its attendant advantages are likewise readily appreciatedfrom the foregoing description. The machine-readable instructionsassociated with control of perforator 222 may be in the form of acomputer program product stored on a non-transitory machine-readablemedium and machine instructions will perform various steps associatedwith drilling a bore in a cranium. For example, in response to executionof suitable machine-readable instructions, perforator tip 228 will bemaintained along trajectory line L during rotation of the perforator bit224 and its advancement corresponding to a desired cranial perforation.

A conical oscillation will be imparted to the perforator bit 224 bysuitable computer control during advancement into the cranium byorbiting the perforator bit 224 at a predetermined radial distance fromtrajectory line L while maintaining the perforator tip 228 aligned withtrajectory line L during such advancement. The resulting conicaloscillation, that is, orbiting of the perforator bit and maintaining theperforator tip aligned with its trajectory lines will define an anglerelative to such trajectory line and such angle has been selected sothat the bore formed upon perforation has a greater diameter than thebit diameter itself. The increased diameter is selected to be sufficientto reduce frictional force opposing withdraw of the bit from the bore.

The above-described orbiting of the perforator bit and maintenance ofperforator tip in alignment with the trajectory line may be selectivelycombined with any number of related operations of robot 102 and itssystem 100, as well as manual operations associated with cranialprocedures. In one possible workflow, while in perforator mode, therobot generates the continuously cycling conical motion as describedabove while still allowing the operator to cause an associatedend-effector 112 to advance or withdraw along the pathway through thecenter of the cone defined by such conical motion. As such, with robotor automatic control of the aforesaid conical motion, a surgeonoperating system 100 can concentrate on causing perforator 222 toadvance as desired to create the planned craniotomy, and the surgeon'soperations may be similar to those associated with advancement withoutsuch conical oscillation. In this workflow, then, the complexity of thesurgeon's manipulations of robot 102 is reduced by removing the need tomanually oscillate the perforator bit while also advancing it.

In another possible workflow, a patient's anatomical coordinate systemis registered to the coordinate system of robot 102 or tracking camerasor other related coordinate systems discussed in this application withreference to the implementations of FIGS. 1-19. A trajectory, includingtrajectory line L, is planned for entry into the cranium by suitablemanipulation of medical images. Robot 102 and its associatedend-effector 112 may be automatically or manually positioned inoperative proximity to the cranium so as to be located and orientedalong desired trajectory line L.

User activation may be used through a suitable interface to startperforator mode at which point robot 102 imparts the conical oscillationto perforator bit 224, namely, keeping perforator tip 228 located at asuitable point along the desired trajectory line L while moving moreperforator bit 224 proximal points away from perforator tip 228 in acircular motion at some radius spaced from the desired trajectory lineL.

Movement of end-effector 112, including components of robot wrist 226,may be effectuated by any suitable manual or automatic means. Forceforward to advance end-effector 112 and perforator 222 secured theretomay be applied manually, either as an initial tap or continuously, ineither event such forward thrust is sensed by a load cell and inresponse thereto, the end-effector 112 and robot wrist move so as toadvance down the trajectory line. Suitable machine-readable instructionsof software may alternately be used so that the perforator 222 isadvanced down the trajectory line and feedback from the load cell 232may be used to control such forward movement, the reduction of reactiveforce signaling the successful perforation of the cranium and ceasingfurther advanced movement in such automatic mode.

Once the cranium has been penetrated the end-effector 112 and itsassociated perforator 222 are moved back up the trajectory line eithermanually using reverse operations of those described previously orautomatically through suitable machine-readable instructions.

Upon completion of the desired perforation or at any other suitablemoment during the foregoing procedures, the perforator mode and itsassociated conical oscillation may be deactivated either in response tocertain conditions as mentioned above or in response to user input.

In those procedures where the robot and its perforator 222 are beingmoved manually, system 100 may include a graphical display of the forcesensed by load cell 232 which may serve as a useful guide to the surgeonas to when such surgeon should stop applying manual force during theperforation procedure. In those circumstances where linear slide 234 isused, rather than oscillating the entire robot arm, in certaincircumstances, quicker disengagement of perforator 222 may beaccomplished because withdrawal of such perforator can be accomplishedby the linear slide 234 while robot arm 104 remains in its position forother related procedures.

As can be understood from the foregoing description, the hole drilledusing either coordinated robot arm movement or advancement of a linearslide 234 would be conical in shape, wherein the deeper the penetration,the larger the hole radius becomes as a wider portion of the fixedconical pattern of drill bit movement cuts bone. In some applications,however, it may be desirable to drill a first hole to the depth of thecranial bone that is then expanded radially without advancing the drilldeeper and damaging brain tissue. In other applications, it may bedesirable to limit the amount of bone dust created while preciselyfitting an implantable surgical device by using a smaller diametercutting bit and continuously adjust the offset of the tip and trailingend of the perforator so that it cuts with a perfectly conical path atall positions longitudinally down trajectory line L. In other words, thecutting pattern at the tip would start as a sweeping circular pattern onfirst penetration and gradually narrow its path of travel until the tipis at or close to a fixed point at final penetration, leaving a conicalcut through bone that has a radius larger than the radius of the drillbit.

To achieve an expanded hole after a first hole is completed and to cutwhile narrowing the path of travel during advancement, the offsets oftip and tail of the perforator relative to trajectory line L would beadjusted automatically or manually at or after different points duringdrill advancement. Adjustment of the cutting path may involve adjustmentof the oscillation imparted to perforator 222 by either robot wrist 226or linear slide 234. Such adjustment would be a function of whereperforator tip 228 and perforator tail are positioned relative totrajectory line L, as described previously with reference to FIG. 22 orwhen not using a linear slide, by altering the commands driving therobot arm to perform its oscillations.

In certain implementations, then, one or more sensors, such as HallEffect sensors, optical tracking, LVDT (linear variable differentialtransformer), resistive wiper, and the like may be used to continuouslyor periodically monitor location of perforator tip 228 and perforatortail relative to the location of linear slide 234 within grooves 236(FIG. 22) and relative to the cranium. Location of perforator tip 228determined by the foregoing sensors will allow suitable instructions ofsystem 100 to calculate and apply the necessary offsets at offset slides246 to create oscillation that is conical or cylindrical withappropriate oscillation radius while appropriately locating perforatortip 228 and tail along the desired trajectory and in turn angling thebalance of perforator bit 224 proximally to achieve a perforation boreof the desired diameter to avoid potential jamming.

In other implementations, tracking of the robot arm through similarsensors may be used to continuously or periodically monitor location ofrobot arm relative to cranium. Location of perforator tip 228 determinedby the foregoing sensors will allow suitable instructions of system 100to calculate and apply the necessary robotic movement to createoscillation that is conical or cylindrical with appropriate oscillationradius while appropriately locating perforator tip 228 and tail alongthe desired trajectory and in turn angling the balance of perforator bit224 proximally to achieve a perforation bore of the desired diameter toavoid potential jamming.

In the above-description of various embodiments of present inventiveconcepts, it is to be understood that the terminology used herein is forthe purpose of describing particular embodiments only and is notintended to be limiting of present inventive concepts. Unless otherwisedefined, all terms (including technical and scientific terms) usedherein have the same meaning as commonly understood by one of ordinaryskill in the art to which present inventive concepts belong. It will befurther understood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of this specification andthe relevant art and will not be interpreted in an idealized or overlyformal sense unless expressly so defined herein.

When an element is referred to as being “connected”, “coupled”,“responsive”, or variants thereof to another element, it can be directlyconnected, coupled, or responsive to the other element or interveningelements may be present. In contrast, when an element is referred to asbeing “directly connected”, “directly coupled”, “directly responsive”,or variants thereof to another element, there are no interveningelements present. Like numbers refer to like elements throughout.Furthermore, “coupled”, “connected”, “responsive”, or variants thereofas used herein may include wirelessly coupled, connected, or responsive.As used herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. Well-known functions or constructions may not be described indetail for brevity and/or clarity. The term “and/or” includes any andall combinations of one or more of the associated listed items.

It will be understood that although the terms first, second, third, etc.may be used herein to describe various elements/operations, theseelements/operations should not be limited by these terms. These termsare only used to distinguish one element/operation from anotherelement/operation. Thus a first element/operation in some embodimentscould be termed a second element/operation in other embodiments withoutdeparting from the teachings of present inventive concepts. The samereference numerals or the same reference designators denote the same orsimilar elements throughout the specification.

As used herein, the terms “comprise”, “comprising”, “comprises”,“include”, “including”, “includes”, “have”, “has”, “having”, or variantsthereof are open-ended, and include one or more stated features,integers, elements, steps, components or functions but does not precludethe presence or addition of one or more other features, integers,elements, steps, components, functions or groups thereof. Furthermore,as used herein, the common abbreviation “e.g.”, which derives from theLatin phrase “exempli gratia,” may be used to introduce or specify ageneral example or examples of a previously mentioned item, and is notintended to be limiting of such item. The common abbreviation “i.e.”,which derives from the Latin phrase “id est,” may be used to specify aparticular item from a more general recitation.

Example embodiments are described herein with reference to blockdiagrams and/or flowchart illustrations of computer-implemented methods,apparatus (systems and/or devices) and/or computer program products. Itis understood that a block of the block diagrams and/or flowchartillustrations, and combinations of blocks in the block diagrams and/orflowchart illustrations, can be implemented by computer programinstructions that are performed by one or more computer circuits. Thesecomputer program instructions may be provided to a processor circuit ofa general purpose computer circuit, special purpose computer circuit,and/or other programmable data processing circuit to produce a machine,such that the instructions, which execute via the processor of thecomputer and/or other programmable data processing apparatus, transformand control transistors, values stored in memory locations, and otherhardware components within such circuitry to implement thefunctions/acts specified in the block diagrams and/or flowchart block orblocks, and thereby create means (functionality) and/or structure forimplementing the functions/acts specified in the block diagrams and/orflowchart block(s).

These computer program instructions may also be stored in a tangiblecomputer-readable medium that can direct a computer or otherprogrammable data processing apparatus to function in a particularmanner, such that the instructions stored in the computer-readablemedium produce an article of manufacture including instructions whichimplement the functions/acts specified in the block diagrams and/orflowchart block or blocks. Accordingly, embodiments of present inventiveconcepts may be embodied in hardware and/or in software (includingfirmware, resident software, micro-code, etc.) that runs on a processorsuch as a digital signal processor, which may collectively be referredto as “circuitry,” “a module” or variants thereof.

It should also be noted that in some alternate implementations, thefunctions/acts noted in the blocks may occur out of the order noted inthe flowcharts. For example, two blocks shown in succession may in factbe executed substantially concurrently or the blocks may sometimes beexecuted in the reverse order, depending upon the functionality/actsinvolved. Moreover, the functionality of a given block of the flowchartsand/or block diagrams may be separated into multiple blocks and/or thefunctionality of two or more blocks of the flowcharts and/or blockdiagrams may be at least partially integrated. Finally, other blocks maybe added/inserted between the blocks that are illustrated, and/orblocks/operations may be omitted without departing from the scope ofinventive concepts. Moreover, although some of the diagrams includearrows on communication paths to show a primary direction ofcommunication, it is to be understood that communication may occur inthe opposite direction to the depicted arrows.

Although several embodiments of inventive concepts have been disclosedin the foregoing specification, it is understood that many modificationsand other embodiments of inventive concepts will come to mind to whichinventive concepts pertain, having the benefit of teachings presented inthe foregoing description and associated drawings. It is thus understoodthat inventive concepts are not limited to the specific embodimentsdisclosed hereinabove, and that many modifications and other embodimentsare intended to be included within the scope of the appended claims. Itis further envisioned that features from one embodiment may be combinedor used with the features from a different embodiment(s) describedherein. Moreover, although specific terms are employed herein, as wellas in the claims which follow, they are used only in a generic anddescriptive sense, and not for the purposes of limiting the describedinventive concepts, nor the claims which follow. The entire disclosureof each patent and patent publication cited herein is incorporated byreference herein in its entirety, as if each such patent or publicationwere individually incorporated by reference herein. Various featuresand/or potential advantages of inventive concepts are set forth in thefollowing claims.

What is claimed is:
 1. A surgical robot system for drilling a hole in acranium of a patient in connection with cranial surgery, the systemcomprising: a surgical robot; a robot arm connected to the surgicalrobot; an end-effector connected to the robot arm and orientable tooppose the cranium so as to be in operative proximity thereto; aperforator connectable to the end-effector and configured to be advancedor withdrawn along a trajectory line relative to the cranium, theperforator having an elongated perforator bit terminating in a sharp,perforator tip, the bit having a bit diameter, the perforator having aclutch operable to engage rotation of the bit in response to resistanceduring advancement of the bit and further operable to stop bit rotationin response to detection of penetration past an internal wall of thecranium; a processor circuit; a memory accessible by the processorcircuit and comprising machine-readable instructions; wherein themachine-readable instructions, when executed, cause the perforator tomaintain the perforator tip along the trajectory line, and further causethe perforator bit to move in a conical oscillation relative to thetrajectory line during the advancement of the bit into the cranium, toform a substantially circular bore having a diameter larger than the bitdiameter by an amount to reduce frictional force opposing withdrawal ofthe bit from the bore after the penetration of the inner wall of thecranium, whereby the risk of jamming of the bit during craniumperforation is reduced.
 2. The system of claim 1, wherein themachine-readable instructions include instructions which, when executed,cause the conical oscillation of the perforator to occur at an anglerelative to the trajectory line ranging from about 1° to about 3°. 3.The system of claim 1, wherein the machine-readable instructions includeinstructions which, when executed, cause the conical oscillation of theperforator to occur at an angle relative to the trajectory line of about2°.
 4. The system of claim 1, wherein the system includes a userinterface and machine-readable instructions comprising a perforatormode, and wherein the machine-readable instructions for causing theconical oscillation of the perforator are executable in response to userselection of the perforator mode through the user interface.
 5. Thesystem of claim 1, wherein the end-effector is connected to theperforator and wherein the end-effector is configured to be manuallyadvanceable down the trajectory line by an amount sufficient to causethe perforator to penetrate the cranium and perforate the inner wallthereof, and wherein the end-effector is manually withdrawable up thetrajectory line after perforation of the inner wall.
 6. The system ofclaim 5, wherein the robot arm includes a robot wrist and a load celloperatively connected to the robot wrist, the load cell configured tosense reactive force corresponding to the perforator bit engaging thecranium, and further configured to detect reduction of the reactiveforce by a predetermined amount, the system further comprisingmachine-readable instructions for generating a user-perceptible signalwhen the perforator is being advanced manually and the load cell detectsthe reduction of the reactive force by the predetermined amount.
 7. Thesystem of claim 1, wherein the machine-readable instructions includeinstructions, executable in response to user activation, to cause theperforator to move down the trajectory line to perforate the cranium andto cause the perforator to move up the trajectory line after theperforation.
 8. The system of claim 7, wherein the end-effectorcomprises a robot wrist and a load cell operatively connected to therobot wrist, and wherein the load cell is configured to sense reactiveforce corresponding to the perforator bit engaging the cranium.
 9. Thesystem of claim 8, wherein the robot wrist is accessible to the user,and the load cell is further configured to sense manual application offorward and rearward force to at least one of the end-effector, therobot arm, and the robot wrist, wherein the machine-readableinstructions to cause the perforator to move down the trajectory lineare executed in response to the sensing of the manually applied forwardforce, and wherein the machine-readable instructions to cause theperforator to move up the trajectory line are executed in response tothe sensing of the manually applied rearward force.
 10. The system ofclaim 8, further comprising machine-readable instructions to controlforward advancement of the perforator in response to input from the loadcell corresponding to the reactive force of the cranium.
 11. The systemof claim 10, wherein the machine-readable instructions for controllingadvancement of the perforator includes instructions, when executed, forceasing advancement of the perforator by the robot arm in response tothe load cell sensing reduction of the reactive force by a predeterminedamount.
 12. The system of claim 1, wherein the perforator is securedrelative to the robot arm and wherein the system includesmachine-readable instructions to move the robot arm in the conicaloscillation.
 13. The system of claim 1, further comprising a linearslide interconnecting the perforator and the robot arm; wherein themachine-readable instructions include instructions to cause the robotarm to impart the conical oscillation to the linear slide, theperforator connected to the linear slide so as to move in the conicaloscillation when the robot arm is moved in the conical oscillation. 14.A surgical robot system for drilling a hole in a cranium of a patient inconnection with cranial surgery, the system comprising: a surgicalrobot; a robot arm connected to the surgical robot; an end-effectorconnected to the robot arm and orientable to oppose the cranium so as tobe in operative proximity thereto; a perforator connectable to theend-effector and configured to be advanced or withdrawn relative to thecranium, the perforator having an elongated bit terminating in a sharp,perforator tip, the bit having a bit diameter, the perforator having aclutch operable to rotate the bit in response to detection by thesurgical robot of resistance during advancement of the bit and furtheroperable to stop bit rotation in response to detection by the surgicalrobot of penetration past an internal wall of the cranium; a processorcircuit; a memory accessible by the processor circuit and comprisingmachine-readable instructions; wherein the machine-readableinstructions, when executed, cause the perforator to maintain theperforator tip along the trajectory line, and, while maintaining aperforator tip along the trajectory line, further causing the perforatorbit to move in a conical oscillation at an angle ranging from about 1°to about 3° relative to the trajectory line during the advancement ofthe bit into the cranium, to form a substantially circular bore having adiameter larger than the bit diameter by an amount sufficient to reducefrictional force opposing withdrawal of the bit from the bore after thepenetration of the inner wall of the cranium, whereby the risk ofjamming of the bit during cranial perforation is reduced; wherein thesystem includes a user interface and machine-readable instructionscomprising a perforator mode, and wherein the machine-readableinstructions for causing the conical oscillation of the perforator areexecutable in response to user selection of the perforator mode throughthe user interface; wherein the robot arm includes a robot wrist and aload cell operatively connected to the robot wrist, the load cellconfigured to sense reactive force corresponding to the perforator bitengaging the cranium, and further configured to detect reduction of thereactive force by a predetermined amount, the system further comprisingmachine-readable instructions for generating a user-perceptible signalwhen the perforator is being advanced manually and the load cell detectsthe reduction of the reactive force by the predetermined amount; whereinthe machine-readable instructions for controlling advancement of theperforator include instructions, when executed, for ceasing advancementof the perforator by the robot arm in response to the load cell sensingthe reduction of the reactive force by the predetermined amount; whereinthe system further comprises a linear slide interconnecting theperforator and the robot arm; and wherein the machine-readableinstructions include instructions to cause the robot arm to impart theconical oscillation to the linear slide, the perforator connected to thelinear slide so as to move in the conical oscillation when the robot armis moved in the conical oscillation.
 15. A computer program product,stored on a non-transitory machine-readable medium, the computer programproduct having instructions to cause a microprocessor to controlmovement of a perforator of a surgical robot system, the perforatorhaving an elongated perforator bit terminating at a distal end in asharp, perforator tip, the bit having an associated bit diameter, theinstructions comprising the steps of: maintaining the perforator tipalong a trajectory line during rotation and advancement of theperforator bit corresponding to a cranial perforation; imparting aconical oscillation to the perforator bit during the advancement intothe cranium by orbiting the perforator bit at a pre-determined radialdistance from the trajectory line while maintaining the perforator tipaligned with the trajectory line during the advancement, the conicaloscillation imparted by the instructions defining an angle relative tothe trajectory line sufficient to form a bore upon perforation of thecranium having a diameter greater than the bit diameter by an amountsufficient to reduce frictional force opposing withdrawal of the bitfrom the bore.
 16. The computer program product of claim 15, wherein thestep of imparting the conical oscillation further includes causing theperforator bit to be displaced by an angle ranging from about 1° toabout 3° relative to the trajectory line.
 17. The computer programproduct of claim 16, the instructions further comprising the step ofimparting the conical oscillation to the perforator in response to useractuation of a perforator mode.
 18. The computer program product ofclaim 16 for use in conjunction a robot arm and a linear slide, theperforator being secured to the linear slide and the linear slide beingmovably mounted relative to the robot arm, the robot arm beingpositionable in a first position relative to a cranial surgical site,the linear slide connected to the robot arm so as be movable relative tothe surgical site independent of movement of the robot arm, theinstructions further comprising the step of causing the perforator tomove relative to the surgical site by advancement of the linear sliderelative to the position of the robot arm.
 19. The computer programproduct of claim 15, wherein the instructions further comprise the stepsof: receiving input corresponding to reactive force generated by contactbetween the perforator bit and the cranium during advancement of the bitthrough the cranium; and in response to signals corresponding to areduction of the reactive force, ceasing advancement of the perforator.20. The computer program product of claim 19, the instructions furthercomprising the step of causing withdrawal of the perforator from thebore previously formed by advancement thereof, the withdrawal beingcaused in response to detection of the signals corresponding to thereduction of the reactive force by a predetermined amount.